This invention relates to endodontal surgery and particularly to procedures and instruments employed therein including absorbent pointed probes utilized as swabs in such as root canal surgery.
While becoming less common in the developed countries through better education of the public in the care of the mouth, the inclusion of antidecay additives to such as the water supply and improvements in dental cleaners and washes, decay of the teeth still remains a common problem. When decay of a tooth is quickly noted and has penetrated the enamel (the outer hard surface of the tooth) and only nominally into the dentin (the calcareous portion as opposed to the pulp and nerve structure) repair is readily made by the treatment of cleaning out the affected tissue of the tooth, replacing it with a synthetic material (such as a dental amalgam). Thus, the tooth is said to have been filled, as by the cavity (formed by the removal of the decayed, diseased dentine) being replaced by the filling material.
If the progress of the decay of the tooth (caries) is allowed to progress into the next inner layer, i.e., the pulp containing the nerve and blood vessels, the required treatment to arrest the continuing decay is likely a "root canal", known from its inclusion in the procedure. When the decay of the tooth reaches the pulp, it likely becomes inflamed and may die. Involvement of the pulp usually results in root-end abscess and the associated infection may be passed by the blood stream to other parts of the body, producing inflammation, secondary abscess or other disease. Endodontic treatment, if initiated immediately after injury or involvement of the pulp, can prevent formation of dental abscess, or if the abscess has developed, can usually eliminate the infection without extraction of the tooth. Removal of the pulp includes removal of the live tissue including the nerves and capillary vessels of the tooth. This procedure includes the cleaning of the hollow, canal-like portions of the tooth extending into the tooth's root, by which it is anchored into the jaw bone. Once the tooth, including the root canal, is completely cleaned, the hollow is filled with an air-tight sealer (commonly including medicaments to destroy microorganisms and promote healing) and the remaining cavity filled with the amalgam, or similar material.
The process of adequately cleaning the root canal is a demanding one, requiring the absolute cleaning and sterilization of the canal, otherwise, a "dead cavity" may result. The "dead cavity" is one in which there is remaining tissue to decompose and cause further disease or abscess and may allow further decay within and adjacent the affected tooth including the surrounding periodontal tissue and occasioning the loss of supporting bone and, ultimately, the tooth. The meticulous process of the "root canal" begins with the removal of the diseased, decayed dentine by drilling and aspiration of that tissue and the underlying pulp. Firstly, the tooth is accessed through the crown of the tooth, being opened by drilling through the enamel to locate the pulp chamber. Once the pulp chamber is accessed the particular diseased canal is measured to determine the length of the canal(s) being treated. It is imperative that in the course of the endodontic procedure that the apical foramen, or opening in the canal to the periodontium, not be pierced such that the periodontium be traumatized at and during the cleaning procedure.
There are two conventional methods for determining the length of the canals. The first involves randomly placing a file in the canal and taking an x-ray to determine if the file is near the apex of the canal (beginning of the apical foramen) and repeating this procedure until the successive x-ray reveals that the file is at the apex of the canal. A rubber stopper is then placed on the "handle end" of the file, snugly against the crown of the tooth. By so noting the extent of the depth of the canal, subsequent scraping and cleaning of the canal may be carried out with assurance that the apical foramen will not be invaded in the successive scraping and cleaning. The second method for locating the depth of the canal is to use an electronic apex locator. This is an instrument which attaches to the file and electronically indicates when the apex of the canal is being approached. It is usual to additionally take an x-ray to verify the reading of the electronic measurement. As previously, a rubber stopper is placed on the file at the working distance to ensure that this extent is not exceeded potentially injuring or traumatizing the periodontium.
Several files are then prepared to the proper working depth. The capillaries and nerves contained in the interstices of the canals within the root are first loosened and scraped with narrow files. Progressively larger files are then used to enlarge the canal to completely clean out the canal and ensure that there is a good stopping point at the end of the canal for the later placement of the packing material. Once the canal is completely opened and cleaned of the with this variety of small files, the canals are then cleaned and dried with absorbent dental points, the subject of the present invention.
As explained above, the adequate cleaning of the root canal requires the dentist to probe, scrape, clean and dry the full extent of the interstices of the canal. Subsequent to the cleaning, a medicament is then applied, irrigating the canal to ensure that all debris is removed and to further sterilize the inside of the canal. Sodium hypochlorite is the solution frequently used for this purpose, taking care that it too, reaches the full extent of the canal.
Disease of the tooth, once penetrating the dentine into the pulp, allows one or more of a variety of microorganisms and bacteria to quickly infiltrate the far reaches of the canal. The same type of absorbent dental point may be utilized to deliver the medicament to the extent of the canal as was used to dry it, being typically dipped into the medicament and then routed down into the canal.
The canal is dried with absorbent "paper points". These are tightly rolled papers in the shape of an endodontic file. These paper points are sequentially placed into the canal to dry the canal of the irrigating solution. As with the files used for scraping, it is necessary to prevent the paper points from violating the apex of the canal. Accordingly, it is necessary to fashion some sort of working depth measure, as with the files. A rubber stopper may not readily or routinely be placed on the paper points for setting the working depth. It has become custom to methodically grasp the paper point with cotton pliers, carefully setting the location of each sequential grasp to the previously identified working depth to ensure paper point penetration into the canal to only the desired depth. As can be appreciated, since a dozen or more paper points are customarily cued in an endodontic procedure, the placement of the pliers and subsequent cumberson manipulation of the pliers in using the point are time consuming and restrictive. Further, the requirement for placement of the pliers accurately and ensuring that there is no slippage creates significant opportunity for error.